1. Field of the Invention
The present invention relates to a piezoelectric power supply converter, and in particular to a power supply converter capable of raising its output power by means of piezoelectric elements.
2. The Prior Arts
Nowadays, more and more portable electronic devices are capable of providing various advanced functions, for example, color screen, stereo audio, hyper links, such as GPRS, wireless network, and Bluetooth, and photo & video recording, Contrast to the existing voluminous and cumbersome portable electronic devices, what the consumers require is that, product design has to be not only of compact size, thin profile, light weight, and easy to operate, but the battery must also be able to provide power for enough long period of operation. This requirement of customer has put circuit design engineer into a dilemma: it must be able to provide much more power to the system and more sets of voltages, yet the space occupied by the power supply equipment and the battery of the portable electronic device has to be reduced steadily.
In order to fulfill all these technical requirements, a design engineer must adopt power supply of higher efficiency, however, in a circuit of an ordinary power supply converter, an ordinary capacitor is connected to an inductor in series or in parallel in realizing resonance effect, however, in case that the voltage of an input signal to an ordinary capacitor is overly large, that would cause pretty large leakage current, thus the efficiency of power transmission is not quite satisfactory. In addition, the voltage endurance of the ordinary capacitor is not sufficient, thus operation failure will result in the explosion of a capacitor, and that is liable to lead to hazards of catching fire. Therefore, the functions and performance of convention power supply converter is not quite satisfactory, and it has much room for improvement